You can also purchase the items mentioned above from other players by visiting the auctionhouses in Fragotown, Fragoville, or Northern Mountains and purchasing if other players are selling those items.

Each green quality pet experience potion has a cool-down timer of 1 minute, so it will take you at least 200 minutes to get your pet from level 1-11. This seems like a long time, but a trusty and well leveled pet can provide the extra bit of damage to help kill that monster, boss, or player.